December 13, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
December 11, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
December 4, 2023: A 22-year-old Quarter Horse mare from Contra Costa County displaying mild neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-4 (EHV-4) on November 30th. The mare is alive and under veterinary care at an offsite veterinary hospital. Fourteen (14) potentially exposed horses at the home premises in Contra Costa County were quarantined on December 1st with enhanced biosecurity measures implemented. There has been no recent history of travel on or off these premises. CDFA was onsite, and will continue to actively monitor the situation.
June 22, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
June 19, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 12, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 6, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 1, 2023: A 25-year-old Quarter Horse gelding in Stanislaus County displaying mild neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on June 1st. The gelding is alive and under veterinary care. Additionally, 4 (four) other horses displaying fever or edema only from the index the premises have also been confirmed positive for EHV-1. The EHV-1 positive horses and 28 potentially exposed horses at the home premises in Stanislaus County have been quarantined with enhanced biosecurity measures implemented. CDFA was onsite, and will continue to actively monitor the situation.
June 6, 2023: The positive horse has had two (2) consecutive negative tests seven (7) days apart. No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
June 1, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
May 30, 2023: A 19-year-old Paint mare in San Luis Obispo county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on May 26th. The mare is currently quarantined under veterinary care at an offsite hospital, also in San Luis Obispo County. Forty (40) potentially exposed horses on the mare’s home premises have also been quarantined. Additionally, out of an abundance of caution, two (2) horses at the offsite veterinary hospital have been quarantined due to low possibility of exposure. The index horse has not had any recent show or travel history. CDFA was onsite to implement enhanced biosecurity on both premises and will monitor the situation closely. No additional clinical signs or cases have been reported since confirmation.
June 1, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
May 30, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
May 23, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
May 18, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation. The quarantine will be released when the positive horse has had two (2) consecutive negative tests seven (7) days apart.
May 14, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
May 9, 2023: An 8-year-old Quarter Horse mare in Modoc County displaying acute neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on May 8th. The mare is alive and under veterinary care. The mare and six (6) potentially exposed horses on the home premises in Modoc County have been quarantined with enhanced biosecurity measures implemented. CDFA will continue to actively monitor the situation.
April 26, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
April 24, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
April 17, 2023: No additional cases have been confirmed. CDFA was onsite and continues to actively monitor the situation.
April 14, 2023: A 25-year-old Quarter Horse gelding in Monterey County displaying fever followed by acute neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on April 13th. The gelding was euthanized due to severity of clinical signs and had no recent travel or show history. Twenty-five (25) potentially exposed horses on the gelding’s home premises in Monterey County have been quarantined with enhanced biosecurity measures implemented. CDFA will continue to actively monitor the situation.
April 13, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
April 11, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
April 7, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
April 4, 2023: An 18-year-old Warmblood gelding in Riverside County displaying neurologic signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on April 4th. The gelding was euthanized due to severity of clinical signs. The index case and its cohort had no recent show or travel history in the past thirty (30) days. There is no known epidemiological link between this case and the previously confirmed active EHM incident in Riverside County. CDFA was onsite at the index premises in Riverside County, and thirty-six (36) additional horses were quarantined with enhanced biosecurity measures implemented.
April 7, 2023: No additional cases were confirmed. The quarantine has been released.
March 30, 2023: All horses, with the sole exception of the last confirmed and isolated positive case, have been released from quarantine following a minimum monitoring period of fourteen (14) days from last known exposure to a positive case. The remaining horse will remain isolated under quarantine until she has had two (2) negative tests seven (7) days apart. No additional cases were confirmed and CDFA will continue to monitor the situation.
March 26, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 21, 2023: A 12-year-old Argentinian polo horse mare displaying mild neurological signs has been confirmed positive for EHM secondary to EHV-1 (non-neuropathogenic strain). The mare was immediately isolated at the onset of clinical signs and is currently alive and under veterinary supervision. Out of an abundance of caution following the confirmation of ongoing viral presence on the premises, the entire facility with 600 horses onsite, previously under voluntary quarantine, has been placed under mandatory quarantine with twice daily temperature monitoring and enhanced biosecurity measures in place. All polo activities in the surrounding area remain voluntarily postponed until further notice. CDFA was onsite, and will continue to closely and actively monitor the situation.
March 16, 2023: A 17-year-old polo horse mare at a polo facility in Riverside County displaying nonspecific lameness followed by severe neurological signs on March 14th was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on March 16th. The mare had not participated in any practices or matches over the past week, and was euthanized due to severity of clinical signs. Nine (9) horses housed with the index case were immediately isolated at an adjacent empty premises and subsequently quarantined with enhanced biosecurity measures implemented. CDFA is working with the attending veterinarian and polo club management to ensure all horses that have visited the polo facility in the past two weeks are monitored closely and owners adhere to biosecurity recommendations both at the polo facility and their home premises. Out of an abundance of caution, all polo activities in the local area have been voluntarily postponed until further notice. CDFA will continue to closely and actively monitor the situation.
March 28, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
March 24, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 20, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 16, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 14, 2023: A 19-year-old Saddlebred gelding at a private boarding facility in Los Angeles County displaying acute neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on March 14th. The gelding was euthanized due to severity of clinical signs. The index case had no recent show or travel history in the past two weeks. CDFA was onsite at the index premises in Los Angeles County, and sixty-one (61) additional horses were quarantined with enhanced biosecurity measures implemented.
March 10, 2023: No additional cases were confirmed during the quarantine monitoring period. The quarantine has been released.
March 7, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 2, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
February 27, 2023: A 9-year-old Quarter Horse mare in San Luis Obispo County displaying acute neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on February 27th. She became acutely neurological on February 22nd, and was subsequently euthanized due to severity of clinical signs. The mare had recently attended a large western discipline event in Tarrant County, Texas from February 10 – 20th, with no clinical signs observed during the event or travel. Event management and Texas state animal health officials have been notified, and all horses attending this event are recommended to monitor temperatures twice daily for 14 days following their departure from the event grounds, and to contact their veterinarian with any concerns. Twenty-six (26) potentially exposed horses on the mare’s home premises have been quarantined, and CDFA was onsite for site assessment and assistance with implementation of enhanced biosecurity measures. CDFA will continue to actively monitor the situation.
January 13, 2023: No additional cases were confirmed. The quarantine has been released.
January 6, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation. The quarantine will be released when the positive horse has had two (2) consecutive negative tests seven (7) days apart.
January 3, 2023: No additional cases have been confirmed. CDFA continues to monitor the situation.
December 27, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
December 23, 2022: A 14-year-old Quarter Horse mare in Riverside county displaying mild neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on December 22nd. The mare is alive and under veterinary care. The mare and four (4) exposed horses on the home premises were quarantined. There has been no recent history of travel on or off this premises.
October 17, 2022: No additional cases to report. The quarantine on this premises was released.
October 13, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
October 10, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
October 6, 2022: A 33-year-old Quarter Horse gelding in Los Angeles county displaying fever and neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (EHV-1, non-neuropathogenic strain) on October 6th. The gelding was euthanized due to severity of clinical signs. CDFA was onsite to implement enhanced biosecurity on October 6th and forty-five (45) potentially exposed horses were quarantined.
August 23, 2022: No additional cases to report. The quarantine on this premises was released.
August 19, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
August 16, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
August 11, 2022: A 8-year-old Quarter Horse gelding originating in Merced county displaying respiratory and neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine Herpesvirus-1 (NEHV-1, neuropathogenic strain) on August 10th. The gelding is currently quarantined in isolation under veterinary care at an offsite hospital. Twenty-eight (28) potentially exposed horses on the home premises were quarantined on August 11th. Neither the index horse nor any horses on the property have had any recent show or travel history. CDFA will assist the home premises in conducting a site assessment and implementing enhanced biosecurity measures, including twice daily temperature monitoring.
June 29, 2022: No additional cases to report. The quarantine on this premises was released.
June 26, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 21, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 17, 2022: One (1) additional horse, a 30-year-old gelding displaying transient fever, has been confirmed positive for EHV-1. CDFA continues to actively monitor the situation.
June 15, 2022: A 20-year-old Quarter Horse gelding in Los Angeles County displaying acute neurological signs was confirmed positive for EHV-1 (wild type strain) on June 14th. The gelding was euthanized due to rapid progression of neurological signs and poor prognosis. CDFA was onsite at the index premises in Los Angeles County, and 9 additional horses were quarantined with enhanced biosecurity measures implemented. The gelding had no recent show or travel history, and there is no known epidemiological links between this incident and any other active EHM incidents. CDFA will continue to actively monitor the situation.
July 20, 2022: No additional cases were confirmed. The quarantine has been released.
July 13, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation. The quarantine will be released whem all positive horses have had two (2) consecutive negative tests seven (7) days apart.
July 5, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation. The quarantine will be released whem all positive horses have had two (2) consecutive negative tests seven (7) days apart.
June 17, 2022: Five (5) additional horses, one (1) displaying transient fever and four (4) with no fever or clinical signs, have been confirmed positive for EHV-1. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
June 14, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 10, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
June 7, 2022: A 7-year-old Holsteiner mare in San Mateo County displaying fever followed by mild neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to EHV-1 (non-neuropathogenic strain) on June 6th. She was referred to a veterinary hospital at onset of neurological signs, and isolated and quarantined. She attended an equine event in Sacramento County the weekend prior, asymptomatic throughout the show, and departing on Saturday May 28th with 5 other horses from her home barn. Event management has notified all show attendees to observe best biosecurity practices and isolate any horses returning from the event for 14 days following departure from the show grounds. CDFA was onsite at the index mare’s home premises, and 9 potentially exposed horses were also quarantined and enhanced biosecurity measures implemented. There is no known epidemiological link between this case and the previously confirmed active EHM incident in San Mateo County. CDFA will actively monitor the situation.
June 17, 2022: No additional cases have been reported in 14 days, and the quarantine has been released.
June 6, 2022: One (1) additional horse on the premises, a 15-year-old Irish Sport Horse mare, displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on June 6th. The mare was euthanized on June 3rd due to severity of clinical signs. CDFA is actively monitoring the situation.
June 3, 2022: A 19-year-old Thoroughbred mare in San Mateo County displaying transient fever on May 28 and neurological signs on June 1 was confirmed positive for EHV-1 (non-neuropathogenic strain) on June 2, 2022. She had no recent travel or show history and was vaccinated for EHV-1. She was euthanized on June 2 due to severity of clinical signs. 300 horses at the mare's home premises in San Mateo County have been quarantined, and CDFA will continue to closely monitor the situation.
April 14, 2022: No additional cases to report. The quarantine on this premises was released.
April 11, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
April 6, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
April 3, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 30, 2022: A 32-year-old Warmblood mare in San Diego county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 29th. The mare was euthanized on March 21st due to severity of clinical signs. CDFA was onsite and the premises with 102 exposed horses were placed under quarantine on March 30th. CDFA will continue to closely monitor the situation.
April 1, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days since the index case was isolated on the home premises, and the index case had two (2) negative tests seven (7) days apart, the quarantine was released.
March 30, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 28, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 26, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 23, 2022: A 14-year-old Quarter Horse mare in Sonoma county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 neuropathogenic strain) on March 22nd. The horse has been isolated at her home premises since March 15th, and was quarantined along with three (3) additional equids on the property on March 23rd. There is no known epidemiological link to any other current EHM incidents. CDFA was onsite at the premises to conduct a site assessment and assist in implementing enhanced biosecurity measures, including twice daily temperature monitoring. CDFA will continue to closely monitor the situation.
March 31, 2022: No additional cases to report. The quarantine on this premises was released.
March 23, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 21, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 18, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 16, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 14, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 11, 2022: One (1) additional horse on the premises, a 21-year-old Thoroughbred gelding, displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 11th. The gelding was euthanized on March 8th due to severity of clinical signs. CDFA is actively monitoring the situation.
March 10, 2022: An 18-year-old Thoroughbred/Percheron cross gelding in Santa Clara county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain). The gelding was euthanized due to severity of clinical signs. CDFA was onsite and the premises with 168 exposed horses were placed under quarantine. CDFA will closely monitor this situation.
March 26, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the home premises, the quarantine was released.
March 11, 2022: One (1) additional horse on the premises displaying fever was confirmed positive for EHV-1 on March 11th. To date, there has been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and two (2) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 9, 2022: A 15-year-old Quarter Horse cross gelding in San Mateo county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on necropsy on March 9th. The gelding was euthanized due to severity of clinical signs. One (1) additional horse displaying fever only with no neurological signs was confirmed positive for EHV-1. CDFA was onsite and the premises with fifty-two (52) exposed horses was placed under quarantine. CDFA will closely monitor this situation.
April 27, 2022: The last horse in isolation has tested negative two (2) times seven (7) days apart. The quarantine on this premises has been released.
April 24, 2022: No additional updates. CDFA continues to monitor the situation.
April 18, 2022: No additional updates. CDFA continues to monitor the situation.
April 13, 2022: No additional cases have been confirmed. One (1) horse remains in isolation awaiting two negative tests seven (7) days apart. All other horses on this premises have been released from quarantine.
March 30, 2022: One (1) additional horse on the premises displaying neurological clinical signs was confirmed positive for EHV-1 on March 30th. The horse is alive and under veterinary care. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-four (24) positive EHV-1 fever-only or mild clinical cases on this premises with two (2) asymptomatic positives off premises but associated with this incident. CDFA is actively monitoring the situation.
March 23, 2022: Two (2) asymptomatic horses from the index premises in Orange county that were permitted movement to their private home premises in Tehama county, were confirmed positive for EHV-1 on March 22nd. The horses, and their exposed cohort of three (3) other horses that were also permitted movement from the Orange county premises, have been isolated and under quarantine on the premises since they arrived.
March 17, 2022: Two (2) additional horses on the premises displaying fever or mild clinical signs only were confirmed positive for EHV-1 on March 17th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-four (24) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 15, 2022: Five (5) additional horses on the premises displaying fever or mild clinical signs only were confirmed positive for EHV-1 on March 15th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-two (22) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 14, 2022: Four (4) additional horses on the premises displaying fever or mild clinical signs only were confirmed positive for EHV-1 on March 14th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and seveteen (17) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 13, 2022: One (1) additional horse on the premises displaying neurological clinical signs was confirmed positive for EHV-1 on March 13th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and thirteen (13) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 11, 2022: Four (4) additional horses on the premises displaying fever or mild clinical signs only were confirmed positive for EHV-1 on March 11th. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and thirteen (13) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 10, 2022: Three (3) additional horses on the premises displaying fever were confirmed positive for EHV-1 on March 10th. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and nine (9) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 9, 2022:One (1) additional horse on the premises displaying fever was confirmed positive for EHV-1 on March 9th. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and six (6) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 8, 2022:Three (3) additional horses on the premises displaying fever or mild clinical signs were confirmed positive for EHV-1 on March 8th. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and five (5) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 4, 2022: A 10-year-old Warmblood gelding in Orange county displaying neurological signs was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 4th. Febrile horses were reported on the premises prior to this EHM case confirmation, including two (2) horses that tested positive for EHV-1. CDFA has been onsite and will quarantine any exposed cohorts. There is no known epidemiological link to any other current EHM incidents at an event premises.
March 30, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the home premises, the quarantine was released.
March 13, 2022: One (1) additional horse on the premises displaying fever or mild clinical signs was confirmed positive for EHV-1 on March 13th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and fourteen (14) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 11, 2022: Three (3) additional horses on the premises displaying fever or mild clinical signs were confirmed positive for EHV-1 on March 11th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and thirteen (13) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 8, 2022:Two (2) additional horses on the premises displaying fever or mild clinical signs were confirmed positive for EHV-1 on March 8th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and ten (10) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 5, 2022:Two (2) additional horses on the premises displaying fever or mild clinical signs were confirmed positive for EHV-1 on March 5th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and eight (8) positive EHV-1 fever-only or mild clinical cases associated with this incident. CDFA is actively monitoring the situation.
March 3, 2022: A 22-year-old Thoroughbred gelding in Orange county displaying neurological signs starting on February 28th was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on March 3rd. Another horse on the premises, a 22-year-old Warmblood gelding displaying neurological signs starting on March 1st was confirmed positive for EHM secondary to EHV-1 on March 3rd. Both geldings were euthanized due to severity of clinical signs. Additionally, six (6) other horses on the same premises displaying fever only or mild clinical signs have positive tests for EHV-1. 350 exposed horses on the home premises have been isolated and quarantined. CDFA will continue to closely monitor this situation.
March 9, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the home premises, the quarantine was released.
March 3, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
February 28, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
February 24, 2022: A 20-year-old Warmblood gelding in Los Angeles county displaying neurological signs on February 22nd was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on February 24th. The horse was euthanized due to severity of clinical signs. This gelding attended a show in Los Angeles county last week and event management has been notified. An investigation is pending to determine if this incident is epidemiologically linked to any other active EHM incidents. The exposed horses on the gelding’s home premises have been isolated and will be quarantined. CDFA will continue to closely monitor this situation.
RELEASED: EHV-1 Quarantine in Orange County
March 24, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the premises, the quarantine was released.
March 16, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
March 14, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
March 11, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
March 10, 2022: One (1) additional horse on the premises displaying fever or mild clinical signs was confirmed positive for EHV-1 on March 10th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-one (21) positive EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 8, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
March 5, 2022: One (1) additional horse on this premises, a 14-year-old Warmblood gelding, displayed neurological signs and was euthanized on March 2nd, and was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on necropsy on March 5th. To date, there have been two (2) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty (20) positive EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 3, 2022: Two (2) additional horses on this premises have been confirmed positive for EHV-1. Both of these positive horses displayed fever only and no neurological signs. CDFA continues to monitor the situation. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and twenty (20) positive EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 2, 2022: Two (2) additional horses on this premises have been confirmed positive for EHV-1. Both of these positive horses displayed fever only and no neurological signs. CDFA continues to monitor the situation. To date, there have been one (1) confirmed EHM case (EHV-1 infection with neurological signs) and eighteen (18) positive EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 1, 2022: Eight (8) additional horses on this premises have been confirmed positive for EHV-1. All of these positive horses displayed fever only and no neurological signs. CDFA continues to monitor the situation.
February 28, 2022: Two (2) additional horses on this premises have been confirmed positive for EHV-1 with five (5) additional presumptive positive horses pending confirmation. All of these positive horses displayed fever only and no neurological signs. CDFA continues to monitor the situation.
February 24, 2022: A 16-year-old Warmblood mare in Orange county displaying neurological signs on February 22nd was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on February 24th. The horse was euthanized due to severity of clinical signs. Additionally, a 10-year-old Warmblood gelding on the same premises displaying fever only with no neurological signs was confirmed positive for EHV-1 on February 24th. The febrile gelding was part of a cohort of horses that attended the event premises in Riverside county that has an active EHM incident, and the neurological mare was exposed to the cohort of horses returning to the home premises from the event in Riverside County. Eighty-six (86) exposed horses on the home premises have been isolated and quarantined. CDFA will continue to closely monitor this situation.
March 2, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the home premises, the quarantine was released.
February 24, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
February 21, 2022: No additional cases or clinical signs have been reported. CDFA continues to monitor the situation.
February 18, 2022: An adult Warmblood gelding in Alameda county displaying neurological signs on February 11th was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to equine herpesvirus-1 (EHV-1 neuropathogenic strain) on February 17th. The horse was afebrile and isolated at his home premises, and was quarantined along with twenty-one (21) additional equids on the property. There has been no movement of horses on or off the property in the past 14 days. There is no known epidemiological link to any other current EHM incidents. CDFA was onsite at the premises to conduct a site assessment and assist in implementing enhanced biosecurity measures, including twice daily temperature monitoring. CDFA will continue to closely monitor the situation.
March 23, 2022: No additional cases to report. As there were no additional cases for fourteen (14) days on the event premises, the quarantine was released.
March 11, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 10, 2022: One (1) additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs on March 9th was confirmed positive for EHV-1 on March 10th. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and thirty-two (32) confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 8, 2022: No additional cases have been confirmed. CDFA continues to monitor the situation.
March 5, 2022: One (1) additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs was confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and thirty-one (31) confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 4, 2022: Three (3) additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and thirty (30) confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 3, 2022: One (1) additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-seven (27) confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
March 2, 2022: Three (3) additional horse on the index event premise, all outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-six (26) confirmed EHV-1 fever-only cases associated with this incident. CDFA is actively monitoring the situation.
February 28, 2022: Two (2) additional horses that had attended the event in Riverside County, one (1) had subsequently returned to their home premises in Sonoma County and one (1) had gone to an offiste veterinary clinic in San Diego county for an unrelated condition, displaying fever only with no neurologic signs were confirmed positive for EHV-1. The horses are currently isolated and under quaratine. Two (2) additional horse on the index event premise, one (1) inside and one (1) outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and twenty-three (23) confirmed EHV-1 fever-only cases associated with this incident. CDFA continues to be on site at the event premises and is actively monitoring the situation.
February 27, 2022: EHV-1 was detected in an asymptomatic horse at an equine event in Sacramento County that had attended the Riverside County event fourteen (14) days prior to the positive test. This horse and the exposed cohort were quarantined at their home premises in Placer County.
February 25, 2022: One (1) horse that had attended the event in Riverside County and had subsequently returned to their home premises, displaying fever only with no neurologic signs was confirmed for EHV-1. The horse is located on the same offsite premises in Riverside county that was previously reported. The positive horse had previously been isolated and has been quarantined on their home premises, along with the exposed cohort. One (1) additional horse on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs was confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and eighteen (18) confirmed EHV-1 fever-only cases associated with this incident. CDFA continues to be on site at the event premises and is actively monitoring the situation.
February 24, 2022: Two (2) additional horses that had attended the event in Riverside county and had subsequently returned to their home premises, or were exposed to horses that had returned home from the Riverside county event premises, displaying fever only with no neurologic signs were confirmed positive for EHV-1. The horses are located in Los Angeles and Riverside counties. There were no additional horses on the index event premises that were confirmed positive for EHV-1 today. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and eighteen (18) confirmed EHV-1 fever-only cases associated with this incident. CDFA continues to be on site at the event premises and is actively monitoring the situation.
February 23, 2022: Three (3) horses that had attended the event in Riverside county and had subsequently returned to their home premises, displaying fever only with no neurologic signs were confirmed positive for EHV-1. The horses are located in Santa Barbara, Ventura and San Mateo counties. The positive horses have been isolated and will be quarantined on their home premises, along with any exposed cohorts. Three (3) additional horses on the index event premise, outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and sixteen (16) confirmed EHV-1 fever-only cases associated with this incident. CDFA continues to be on site at the event premises and is actively monitoring the situation.
February 21, 2022: Four (4) additional horses on the event premises, one within the index quarantine barn and 3 housed outside of the index quarantine barn, displaying fever only with no neurologic signs were confirmed positive for EHV-1. The positive horses have been placed in isolation and all horses in the exposure cohorts are isolated and under quarantine. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and nine (9) confirmed EHV-1 fever-only cases for this incident. CDFA continues to be on site at the premises and is actively monitoring the situation.
February 19, 2022: Two (2) additional horses on the event premises housed outside of the index quarantine barn displaying fever only with no neurologic signs were confirmed positive for EHV-1. The positive horses have been placed in isolation and all horses in the exposure cohorts have been quarantined and isolated on the index premises. One of the previous EHV-1 positive horses that displayed neurologic signs was euthanized due to severity of clinical signs. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and five (5) confirmed EHV-1 fever-only cases for this incident. CDFA continues to be on site at the premises and is actively monitoring the situation.
February 18, 2022: One (1) additional horse on the event premises housed outside of the index quarantine barn displaying fever only with no neurologic signs was confirmed positive for EHV-1. The positive horse has been placed in isolation and all horses in the exposure cohort have been quarantined and isolated in a separate area on the index premises. Two previous fever-only EHV-1 positive horses that were already in isolation have shown neurological signs and are under veterinary supervision. To date, there have been three (3) confirmed EHM cases (EHV-1 infection with neurological signs) and three (3) confirmed EHV-1 fever-only cases for this incident. CDFA continues to be on site at the premises and is actively monitoring the situation.
February 15, 2022: Two (2) additional horses in the quarantined barn at the event premises displaying fever only with no neurological signs were confirmed positive for EHV-1. CDFA continues to be on site at the premises and is actively monitoring the situation.
February 11, 2022: A 12-year-old Zangersheide gelding displaying neurological signs on February 10th was confirmed positive for Equine Herpesvirus Myeloencephalopathy (EHM) secondary to Equine herpesvirus-1 (EHV-1 non-neuropathogenic strain) on February 11th. The gelding is currently attending an equestrian event in Riverside County and has been isolated at the event premises. Two (2) additional horses displaying fever only that were housed in the same barn on the premises have also been confirmed positive for EHV-1 and isolated. The three (3) affected horses in addition to 45 horses housed in the exposed barn on the premises have been quarantined. CDFA staff was onsite at the event premises on February 11th to conduct a site assessment and assist in implementation of enhanced biosecurity measures including twice daily temperature monitoring and prompt isolation of any horses displaying fever or neurological signs. CDFA will continue to actively monitor the situation.
March 31, 2022: The last horse in isolation has tested negative two (2) times seven (7) days apart. The quarantine on this premises has been released.
March 28, 2022: No additional cases have been confirmed. One (1) horse remains in isolation awaiting two negative tests seven (7) days apart. All other horses on this premises have been released from quarantine.
March 14, 2022: One (1) additional horse from the index premises displaying fever only with no neurological signs was confirmed positive for EHV-1 on March 14th. To date, five (5) EHM cases (EHV-1 positive with neurologic signs) and thirty-five (35) EHV-1 febrile only cases have been confirmed. CDFA continues to actively monitor the situation.
March 11, 2022: One (1) additional horse from the index premises displaying neurological signs was confirmed positive for EHV-1 on March 11th, and has been isolated at the index premises. Additionally, two (2) horses displaying fever only with no neurological signs were confirmed positive for EHV-1 on March 11th. To date, five (5) EHM cases (EHV-1 positive with neurologic signs) and thirty-four (34) EHV-1 febrile only cases have been confirmed. CDFA continues to actively monitor the situation.
March 8, 2022: One (1) additional horse from the index premises displaying fever only with no neurological signs was confirmed positive for EHV-1 on March 8th, and has been isolated at the index premises. Additionally, one previously febrile only EHV-1 positive horse began showing neurological signs. To date, four (4) EHM cases (EHV-1 positive with neurologic signs) and thirty-two (32) EHV-1 febrile only cases have been confirmed. CDFA continues to actively monitor the situation.
March 4, 2022: Three (3) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on March 4th, and have been isolated at the index premises. To date, three (3) EHM cases (EHV-1 positive with neurologic signs) and thirty-two (32) EHV-1 febrile only cases have been confirmed. CDFA continues to actively monitor the situation.
March 3, 2022: Four (4) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on March 3rd, and have been isolated at the index premises. To date, three (3) EHM cases (EHV-1 positive with neurologic signs) and twenty-nine (29) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 28, 2022: No new cases to report. CDFA continues to actively monitor the situation.
February 25, 2022: Two (2) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 25th, and have been isolated at the index premises. To date, three (3) EHM cases (EHV-1 positive with neurologic signs) and twenty-five (25) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 23, 2022: Two (2) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 23rd, and have been isolated at the index premises. Additionally, one (1) horse from the index premises displaying neurological signs was confirmed positive for EHM secondary to EHV-1 and was isolated at an offsite veterinary hospital. To date, three (3) EHM cases (EHV-1 positive with neurologic signs) and twenty-three (23) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 22, 2022: Four (4) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 22nd, and have been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and twenty-one (21) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 18, 2022: No new cases to report. CDFA continues to actively monitor the situation.
February 16, 2022: One (1) additional horse, a 19-year-old Draft cross gelding, from the index premises displaying fever only with no neurological signs was confirmed positive for EHV-1 on February 16th, and has been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and seventeen (17) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 15, 2022: Four (4) additional horses from the index premises displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 15th, and have been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and sixteen (16) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 10, 2022: One additional horse from the index premises, a 15-year-old Thoroughbred gelding, displaying fever only with no neurological signs was confirmed positive for EHV-1 on February 9th, and has been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and twelve (12) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 8, 2022: Two additional horses from the index premises, an 11-year-old Warmblood gelding and a 20-year-old Warmblood mare, displaying fever only with no neurological signs were confirmed positive for EHV-1 on February 8th, and have been isolated at the index premises. To date, two (2) EHM cases (EHV-1 positive with neurologic signs) and eleven (11) EHV-1 febrile only cases have been confirmed. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 7, 2022: One additional horse from the index premises, a 10-year-old Quarter Horse gelding displaying fever with no neurological signs on February 5th was confirmed positive for EHV-1 on February 7th and has been isolated at the index premises. The quarantine will be released when all positive horses have had two (2) consecutive negative tests seven (7) days apart. CDFA continues to actively monitor the situation.
February 4, 2022: Two additional horses from the index premises, a 12-year-old Warmblood gelding and a 25-year-old Appaloosa gelding, displaying fever on January 30th and February 3rd respectively with no neurological signs, were confirmed positive for EHV-1 on February 4th. The Warmblood gelding was transported to a veterinary clinic and has been isolated there, and the Appaloosa gelding has been isolated at the index premises. CDFA continues to actively monitor the situation.
February 2, 2022: One additional horse from the index premises, a 15-year-old Quarter Horse mare, displaying fever only on January 27th was confirmed positive for EHV-1 on February 2nd, and has been isolated on the premises. CDFA was onsite at the premises, and continues to actively monitor the situation.
January 31, 2022: One additional horse from the index premises displaying neurological signs on January 29th, a 17-year-old Arabian/Quarter Horse gelding, was confirmed positive for EHV-1 on January 31st. He was transported to a veterinary referral clinic on January 29th and remains isolated under quarantine at the veterinary clinic. Three additional horses from the index premises displaying fever only, a 15-year-old Quarter Horse gelding, a 17-year-old Quarter Horse gelding, and a 7-year-old Warmblood/draft gelding have also been confirmed positive for EHV-1. CDFA continues to actively monitor the situation.
January 29, 2022: A 22-year-old Paint gelding with acute onset of neurological signs on January 28th was confirmed positive for EHV-1, non-neuropathogenic strain, on January 28th. The horse was afebrile and isolated at his home premises, and was quarantined along with 300 additional horses on the property. He was euthanized due to poor prognosis. Two additional horses at the property, a 19-year-old Arabian gelding that was transiently febrile the week prior and sent to a referral hospital on January 24th, and a 15-year-old Thoroughbred gelding that was transiently febrile on January 24th, were both tested on January 24th and confirmed positive for EHV-1. The Arabian gelding remains isolated and quarantined offsite at the referral hospital. The Thoroughbred gelding traveled to and from an equine event on January 23rd prior to clinical signs, and event management was notified. CDFA was onsite at the premises to conduct a site assessment and assist in implementing enhanced biosecurity measures, including twice daily temperature monitoring. CDFA continues to closely monitor the situation.
February 16, 2022: The index case has been released from quarantine at her home premises in Sonoma County following confirmatory negative testing.
February 10, 2022: The index case remains under quarantine at her home premises in Sonoma County pending two (2) consecutive negative tests seven (7) days apart. CDFA continues to monitor the situation.
February 2, 2022: The index case remains under quarantine at her home premises in Sonoma County pending two (2) consecutive negative tests seven (7) days apart. CDFA continues to monitor the situation.
January 26, 2022: The quarantine at the Alameda County racetrack has been released as there were no additional clinical signs or cases confirmed during the fourteen (14) days following removal of the index case from the premises. The index case remains under quarantine at her home premises in Sonoma County pending two (2) consecutive negative tests seven (7) days apart. CDFA continues to monitor the situation closely.
January 25, 2022: No additional cases to report. CDFA continues to monitor the situation closely.
January 20, 2022: An 8-yr-old Thoroughbred mare in Alameda County displaying neurological signs on January 12th was confirmed positive for EHV-1 on January 19th. The mare resided at a racetrack and was transported to her home barn in Sonoma County and isolated on January 12th following the onset of clinical signs. The mare has been quarantined at her home premises and will be released following 2 (two) consecutive negative tests seven days apart. Fourteen horses from the index mare’s training barn have been isolated and quarantined, and have been tested and confirmed negative for EHV-1, and an additional thirteen horses from the adjoining training barn have also been quarantined, with no additional clinical signs or cases detected at the racetrack. CDFA was onsite to conduct a site assessment and implement enhanced biosecurity measures including twice daily temperature monitoring. Site assessment at the racetrack confirmed no known exposure beyond the barn identified, and there has been no evidence of ongoing disease transmission.